Eighth seed Strycova had little answer to her opponent’s venomous hitting and the world number seven bagged the first set with a sledgehammer forehand that almost tore the racquet from the Czech’s hand.

The 20-year-old Osaka, contesting her first tournament since becoming Japan’s first Grand Slam singles winner, never looked back against a player 12 years her senior, another forehand rocket bringing up a first match point.

Strycova saved that one but moments later, Osaka fired a bruising serve into the body to extend her current winning streak to nine matches.

“I’ve played her three times and each time it’s been very hard,” said Osaka, who reached the Tokyo final in 2016.

“I don’t feel any extra pressure playing in Japan,” added Japan’s latest sporting celebrity, who has a Japanese mother, a Haitian father and was raised in the United States.

“I’ve improved a lot of things in the last few years and I feel excited playing here.”

Earlier, fourth seed Karolina Pliskova saved two match points before the former women’s top-ranked player ended American qualifier Alison Riske’s run with a 6-1, 6-7 (5/7), 7-6 (7/4) victory.

The Czech, who smashed a racquet in disgust after squandering multiple chances at 5-5 in the deciding set, completed a “lucky win” with a sliced backhand that Riske wafted into the net after two hours, 40 minutes.

“It was an important win for me,” said Pliskova after reaching her first Tokyo semi-final.

“I saved a couple of match points — she was a little bit better than me but you need a bit of luck in tennis. I’m just happy to be able to fight back.”

Pliskova faces Croatia’s Donna Vekic in the last four after she upset second seed Caroline Garcia 6-3, 6-4.

Garcia blew an early break to allow Vekic to take the opening set and the Frenchwoman suffered a carbon-copy letdown in the second, the Croatian ending her misery with a backhand winner.